Porto
The northern capital sits in a steep amphitheatre over the Douro River, with the famous port wine cellars on the Vila Nova de Gaia side connected by the iconic Dom Luís I bridge. The Ribeira waterfront is the postcard; the Livraria Lello bookshop is the architectural marvel that allegedly inspired the library scenes in Harry Potter; São Bento railway station has 20,000 azulejo tiles depicting Portuguese history. Eat francesinha (a meat-stacked sandwich smothered in beer-tomato sauce) and tripas à moda do Porto. Day trip up the Douro Valley for the wine country.